Motor suspension



iI ii'neav G. R. GOLDTHWAITE Io'roR SUSPENSION oat-1 1933, 1,930,971

Filed March 12, 1931 2 Sheets-Shae}. 1

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I 45 ng surfaces 21 and bolt holes 22 to receive bolts oscillations, they are effectively damped out when 100 Patented Oct. 17, 1933 l MOTOR SUSPENSION George R. Goldthwaite, Readville, Mass, assignor to B. F. Sturtevant Company, Hyde Park, Mass, a. corporation of Massachusetts Application March 12, 1931. Serial No. 521,943 2 Claims. (01. 248.-- 16)' The present invention relates to motor suspension as in Fig. 2, the forces acting downwardly sions, and more particularly to motor suspensions upon. the spring are symmetrically distributed, for motors designed especially for the direct drivand the forces acting upon the pivots 13 are subing of fans in ventilating apparatus. stantially identical. Under such conditions the I One of the objects of the present invention is device as illustrated in Fig. 2, but without the 00 to provide a motor suspension of simple design spiral springs (shown'in dotted outline) is adeand inexpensive.- construction which will serve quate. When the motor is hung from the susadequately to support a motor and its fan in pension attached to a vertical support as is operation. l illustrated in Fig. 3, the forces acting upon the Another object of the invention is to provide suspension are not symmetrically disposed, and a bearing suspension which will absorb starting the forces acting upon the pivots 13 differ in torques and the vibrations set up by the motor amount and direction, for the force upon the and fans in operation, thus substantially elimiupper pivot is one of tension while the force upon nating noise and hum. the lower pivot is one of compression. In a sus- 15 With these and other objects in view as will be pension of this kind, a spiral coil spring 28 is apparent to one skilled in the art, the present inserted between the bosses 17 to relieve the invention consists of the device hereinafter delower pivot and the lower portion 0f the threescribed and claimed. quarter loop spring of some of the stresscreated The invention in its preferred form is illusby the weight of the motorand fans. -A tens'ion 20 trated in the' accompanying drawings in which Spr ng may be inserted between and tied to Fig. 1 is a front elevation of a motor and fans the bosses 17, thus serving to relieve the upper mounted upon the suspension in a ventilating pivot 13' of some of the force of tension. device; Fig. 2 is a side elevation along the section Fig. 4 illustrates a simplified embodiment of 22 of Fig. 1; Fig. 3 is a side plan view of the the invention. In this form, the overhung three- 25 suspension attached to a vertical support with quarter loop spring 10 is pivotally mounted at 13 a motor hung therefrom, and Fig. 4 is a side plan directly upon the metal plates 14 attached by bolts view of a motor mounted upon a simplified form and nuts 15 to the support 16. The modification of the invention. is essentially suited to the positioning of the mo- The device illustrated in the drawings of Figs. tor and fans in the position indicated, while the 30 1, 2 and 3, which show one-half of the suspension, preferred embodiment of the invention as illuscomprises an overhung three-quarter loop spring trated by Fig. 2 is suite-d to the positioning of the 10 rigidly attached at its ends by bolts and nuts motor and fans either upon, or hung from the 11 to the members 12 which are pivotally mountsuspension. 1 ed at 13 upon the metal plates 14 attached by The mode of operation of the invention is as 35 bolts 15 and nuts to the support 16. These plates follows: The motor and fans are mounted upon 14 and the members 12 are provided with bosses the suspension and fixed thereupon by the bolts 17, to receive the spiral springs 28 shown in dotted 19 and 19. The motor circuit is then closed. The outline, the purpose of which will-later be devibrations due to the motor and to any imperfec-' scribed. Attached by the attaching surface 21 tion in the balancing of the fan blades are com- 40 upon the top portion of the spring 10 at the point municated to the overhung three-quarter loop of greatest flexibility, and held thereto by bolts spring, presumably setting up transverse waves 19 is the motor bearing 20 which is cast en bloc and longitudinal oscillations therein. From exwith the end plate of the motor frame. The perimental results, the conclusion follows that motor bearing is provided with additional attachwhatever may be the character of these waves and to permit the attachment of the motor to the they reach the portion of greatest curvature of the suspension as illustrated in Figs. 2 and 3. Within three-quarter loop overhung spring, for they do the bearing 20 is the motor shaft 23. not communicate any substantial amount of en- Into the bearing 21 is screwed the oil conduit ergy to the pivots 17 and'thence' to the support 16.

24 provided with the oil cup 25 and its cover 26. The result of the use of this invention is the al- The side of the oil cup is provided with a threaded most complete elimination of all sound of operahole closed by the plugs 27, which may be retion.

moved, thus permitting the cleaning of the oil 'While the present invention has been shown conduit. and described as embodied in a suspension for 55 When the motor is mounted upon the suspenelectric motors, it is to be understood that it is 'ing a pair of spring-receiving seats spaced apart in the direction of the axis of the shaft of the motor, a support, and means for resiliently suspending said motor on said support embodying a pair of leaf springs arranged at right angles to the shaft of the motor, one at each end of the motor, each of said leaf springs being of the three-quarter loop type aflixed midway its length to its companion spring-receiving seat and having its free ends curved inwardly toward each other and pivotally connected to said support at a fixed distance apart.

2. The structure recited in claim 1, the connection of each of the ends of the spring to the frame embodying a bar projecting outwardly beyond the curved end of the spring, and a coil spring interposed between the outer end of this bar and the support whereby when the motor is mounted so that the leaf springs shall be in a vertical position one pair of these coil springs will act as compression springs.

GEORGE R. GOLDTHWAITE. 

